Rootstocks

Question 1

General info

Answer 1

• Most rootstocks are hybrids of Rupestris, Riparia, Berlandieri
• Rupestris = drought tolerant, vigorous, deep-rooting, late-ripening, can suffer chlorosis
• Riparia = damp tolerant, shallow-rooting, early-ripening, low vigor, can suffer chlorosis (iron deficiency) on chalky soils. Also fairly cold-hardy
• Berlandieri = essential for lime tolerance, very vigorous and deep rooting. Rarely used as a pure species because of difficulty rooting. Also inefficient at potassium uptake so acidity is retained in the wine

Question 2

SO4

Answer 2

• Cross of Riparia x Berlandieri
• Shallow roots
• Good tolerance for damp soils and chalk
• Can have issues taking up magnesium in soil
• Moderate resistance to nematodes
• Devigorating

Example: used by Ridgeview in Sussex, England that has high chalk but damp soils

Example: Catena in Argentina uses to resist nematodes

Question 3

41B

Answer 3

• Cross of Chasselas x Berlandieri
• Highly resistant to lime
• Weak to drought, phylloxera, nematodes
• Used widely in Champagne and Cognac (is 80% of rootstock in Champagne)
• also seen in most calcareous parts of Rt Bank for Merlot, but there it is being replaced by Fercal rootstock

Example: Rodolphe Peters says he has “no choice” but to use exclusively 41B due to the high lime content of the Cotes des Blancs

Question 4

039-16

Answer 4

• vinifera x rotundifolia
• Strongly Nematode resistant, but also highly vigorous.

Example: Almost all of To Kalon is on this stock.

Example: Kelly Maher and Pete Richmond use it, plant lots of grasses and cover crop to compete for water and nutrients.

Question 5

Riparia Gloire

Answer 5

• Entirely Riparia.
• Good lime tolerance.
• One of the three most widely used rootstocks in Oregon, because it is early ripening, helps to shorten the long season.

Example: Mike Hirby planting a small 1.5 acre vineyard in Soda Canyon. As it is a tiny vineyard there are no vines to spare. Since end vines typically ripen later (no competition), he is planting them on Riparia Gloire, as it is early ripening and less vigorous. The thought is that this will make the end vines ripen at same time as main vines (planted on 3309)

Example: widely used by Dujac (along with 161-49, 3309, and 34EM) for its lime tolerance

Question 6

St. George

Answer 6

“Rupestris du Lot” AKA entirely Rupestris

• Historic anti-phylloxera rootstock of California.
• Clone 7 on St. George responsible for nearly all the great old school Napa Cabs of the 1960s and 70s.
• Is very drought resistant, vigorous, and prone to shatter.
• Known for longevity
• Good tolerance for salinity

Example: Because of shatter, Tegan Passalacqua at Turley avoids it for Zinfandel as it exaggerates the variety’s tendency for differential ripening.

Question 7

110R

Answer 7

• Berlandieri x Rupestris
• Good for drought resistance and dry farming.
• Poor assimilator of K+, good for volcanic sites, per Kelly Maher.

Example: Used widely by Harlan.

Question 8

101-14

Answer 8

• Riparia x Rupestris
• Cold hardy
• Kelly Maher says this is a bad rootstock for many sites in Napa as many sites are volcanic (AKA high in Potassium) and 101-14 absorbs K+ and drives up the pH.
• Fred Wiemer uses widely for cold-hardy in FLX

Question 9

3309

Answer 9

• Riparia x Rupestris
• very cold hard, susceptible to nematodes, moderate to high vigor
• Most widely used rootstock in eastern US esp FLX